Mix mayo and pesto together and spread on bottom half of baguette. Spoon olive oil over other half.
Place tomato slices on bottom half of baguette, each slice overlapping the last slightly. Add mozzarella slices on top. Season with salt and pepper.
Melted caprese: Place sandwich is broiler for several minutes until mozzarella is melting slightly. Remove from oven.
Drizzle mozzarella and tomatoes with balsamic glaze and layer basil leaves over. Top sandwich with other half of baguette.
Cut in half and serve with a bowl of olive oil for dipping.
Cooking option: Can also use panini press or indoor grill machine
Mozzarella: Use mozzarella di bufala (mozzarella made with water buffalo milk) if you can find it.
Tomatoes: Don't refrigerate. Keep at room temperature for the best taste. If they are watery and not flavorful, sprinkle tomato slices with salt and let them sit for about 30 minutes prior to making sandwich.